Invincible comic book were created by Robert Kirkman, creator of The Walking Dead. The Concept: Mark Grayson is a normal American high School student. The only difference between Mark and everyone else is that his father is the most powerful superhero on the planet, and as of late, he seems to be inheriting his father's powers. Which sounds okay at first, but how do you follow in your father's footsteps when you know you will never live up to his standards?